Decatted headpipe vs aftermarket

[BlackSpecial]

That was when the bike had just a stage 1.

Stock cams, TTS, Mellows, Ness a/c, 2014 SGS

[Tireman]

No matter what you guys might think I have seen built and tuned enough bikes to know that the stock decatted pipe will NOT be on par with a good x pipe once cams are installed. If you do feel the need to use the decat at the very least tack a 2 inch long piece of pipe in the chamber before you weld it back up effectively making the headpipes a tad longer and eliminatingg the cross talk problem

Just had this exact same issue with a friends '13 FHLTR last week. He decatted himself on the bike!!!!!. I put TW777 cams, Mega Flo heads ...who warned me about the pipe! When we took it to the tuner he couldn't get the pipe to tune. Tuner said the 02 sensors were cross talking do to the mods we made. Put a Fulsac DX on an wala bike tuned and turned out great. 

[HD/Wrench]

stock cams or small cams do not do it as bad but as the cams get larger the cross talk most times becomes more of an issue.. As Bob said weld in a piece of steel to stop the sensors from seeing each other and it works but really a good after market pipe will yield better results.

[Jamo11]

The de-catted Harley head pipe works pretty good. The Jackpot 2 into 1 into 2 also works very good. Additional heat is retained by the shear mass of Harley. There's a big lump of metal where the cat used to be that collects and holds heat.

The Jackpot is a lot lighter and I feel a little more power. I think it has bungs for an PCV auto-tuner. But it is still pretty hot.

If I had it to do over again, I'd a kept my D & D 2 into 1. But I sold it.

[1FSTRK]

This is not a back to back test but it sure is a good running bike for a modified stock exhaust system.
http://harleytechtalk.com/htt/index.php/topic,72955.msg795650.html#msg795650

[Piston Broke]

I notice the 2-1-2 pipe has a kind of step down ... to match the mufflers. Is that standard on all the models, even the ones with the active valve in it?

Looking at a picture of the latter (last below), I don't see one.

Looking to retro-fit one to an Evo.

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[Piston Broke]

Ah ... problem solved. The 'drop muffler' edition is for the Trikes.

[garsam]

Wondering what you all think of decating on a stock 2 into 1 exh. such as on a 2014 low rider vs. using an after market head pipe. is the o2 senor still an issue?

[sfmichael]

Rush has a pipe for under the stock shields, not crazy about the fitment but it does work well.  Bassani has one for under the heat shields and if you check out Dennis Kirk there is an X pipe produced by Hellbent that works very well. As for the best value it's hands down this one from Danmoto  https://www.dan-moto.com/DM_US/touring-wholesale-18_186_190.html  I have used them and the shields fit better than the pipes that cost twice the amount and the performance is on par with the best of them

thanks for the link Bob...looks like a great value 

[Buglet]

   Just did a 15 SG  all stock except a decatt head pipe, had a 11 HP increase and also TQ increase low end 9, mid 5, and top 11. This is with stock air cleaner and mufflers. 

[Brrrap]

  I have only been a few weeks with my 2016 FLHTP (Police). Hated the heat, @ 1400 miles installed the Rush Racing products "True Dual's" and a DynoJet tuner module. Dyno tuned the bike and my results look to be a gain in H.P. that was 73.713 now 81.94 The torque gains went from 94.973 up to 101.85 if I'm reading my dyno sheets correctly.
I have the receipt showing the cost of the true Dual's at $287.95 and my stock heat shields are installed over them. I'm really liking this bike.
Oh and other than the tuner and pipes, the bike is stock, running through the stock mufflers.

[Johnnyglide]

   Just did a 15 SG  all stock except a decatt head pipe, had a 11 HP increase and also TQ increase low end 9, mid 5, and top 11. This is with stock air cleaner and mufflers.

Buglet, is this with no tune?

[Matt C]

Pipes are an amazing aspect of IC engines. They look and seem so simple yet they're probably
(one of) the most misunderstood parts.

There's so much that goes on in modern exhaust systems that it's literally mind boggling. The
textbooks and SAE papers written on these things can make even the most experienced engineers'
heads spin.

Don't assume that just b/c a pipe looks like it should do great things that it actually will. 

Added:

My hat goes off to the guys that design and build successful pipes so we don't have to.

[Buglet]

    With the stock pipe it had a canned map, with the decatted pipe it was tuned with PV.